Regulating device



Aug, 15,, 3950 s. H. BUDER ETAL 2,519,173

REGULATING DEVICE Filed June 12, 1946 MM 1 Vail 45f Q a JUPPA/F/ 7' r1 I i i I 5 INVENTORE Patented Aug. 15, 1950 REGULATING DEVICE Spurgeon H. Buder, Merchantville, N. J., and William H. Eichelberger, Denver, 0010., assignors to Radio Corporation of America, a corporation of Delaware Application June 12, 1946, Serial No. 676,167

Claims. (Cl. 315-107) This invention relates to regulating devices of the type which are suitable for regulating the cathode heating current of an electron discharge element so as to maintain a current of constant termines the value of its anode current and of the impedance of the impedance device which is connected in its anode circuit.

Important objects of the invention are the provalue in the outputof such element. 5 vision of an improved regulating device and In the operation of various types of equipments method of operation for maintaining a constant including an electron discharge element, it is value in the output current of an electron gun, desirable that the cathode heating current of the d th provision of an improved regulating el e e SO regulated that the u p cullfllll device which functions to vary the impedance of is maintained within very narrow ll l s, la cathode heating circuit in accordance with the itlantially tconstailitt inespeicgived of variat on i zlalue oft a unidirectional potential dependent on 6 Opera mg v ages 0 e evlce. nus m e elec ron cmisslOn of such cathode. the case of a lens C a n equipment wherein The invention will be better understood from the coating is hardened by bombardment With 3412. the following description considered in 60111180.. electron gun, for example, the requirement that t t t accom a in drawin n '1; the lens coating be uniformly treated rnakes it scope i i dic t d by tie gpp nded clai ms d 1 s is; d a A iagram o a regula ing device connected and gala gaig gi shg g igggc: bombardmg of arranged in accordance with the present inven- 0 Hg 8 tion. In accordance with the present invention, the This figure Shows an electron gun which gif egiq gfigzlgfig, ilallcellgevbill bg giggle; includes a cathode iii, an anode H, a focus coil v r [2, a hi h s ee swee defle tio l device which includes (1) a variable impedance low g g c0101 g g g: 3 ionzlected m g ggi f zi i fg rent is supplied to the cathode it from the altergr n ill b e fg 2 25; 6 1- g nating potential input terminals i5-l 5 through nected to control the im edance of the ir pedtransformer {IT-4 and Variable impedance ance means and (3) me 5 fbr applying um I device which includes a transformer T2 and control grids of the electron tubes a bias potential 22 5 g i ?g. illectron g i q which is the resultant of a potential having a 6 en 8 an W m have anconstant value and a potential having a value odes comtectfed 1n push'puu relation t0 Um See- .which is proportional to the output current of the onfiary wltldlrig t transformer tne electron gun 7 primary winding of this transformer being con- Under the'se Conditions there are applied to nected in series with the heating circuit of the the control grids of the tubes (1) an alternating ig '31 in m potential which has a predetermined phase re- A g 1a} i fl j ig lation with that applied to the impedance de- 1 5 H5]1s p q to bkle and Vice and the Cathode heating circuit of the 618? V of the e-ectron discharge elements V-4 and tron gun, and (2) unidirectional bias potential 40 through a.t1ansf0me1 T 3 Whlch which is proportional to slight variations of the secondaf'y Wmdmg shuntajd Output current of the gun so that the impedance R6 and R'! and the capac tors C2 arm of the impedance means connected in the cath- P that a P pftelltlall applied to ode heating circuit increases when the output the grlds througil me 9P4 current of the gun tends to increase and vice a B neutral lead of me Secondary versa Winding 2!! is connected to the anode l! of This action results from the well known fact gun 1S P f that the current conduction of a gaseous dis- Operating potential is applied. between the charge tube (sometimes designated as a h cathode Ill and the anode ll of the electron gun t ma b started at any desired point in V2 from a pair of terminals 22-23 through the positive half cycle of its anode voltage by varying the bias potential of its control grid relative to its cathode. Thus the part of the positive half during which the triode conducts dea resistor R-2 which is adjustable to produce a voltage E2. This voltage is balanced against that of a constant voltage device V-l which is connected between the terminals 22 and 23 through a resistor R-| and functions to produce a constant voltage E-l.

The resultant difference voltage E-3 of the voltages E-I and E-Z is applied between the neutral lead 2| and the cathode return lead 24 of the devices V4 and V5 so that the oathodes 25 and 26 are maintained at a bias potential dependent on the value of the voltage E3. Rapid fluctuations in this voltage are smoothed out by a filter R-3 and C-l, and the discharge device V-3 functions to limit the voltage that can be applied to the cathodes 25 and 28 under abnormal conditions.

If the voltage E2 is small compared to El, the voltage E-3 from the cathode lead 24 to the grid return lead 2| is more positive thus causing a wider angle of current flow in the devices V- l and V-5, lowering the impedance of the transformer T2, increasing the temperature of the cathode I!) and increasin the current of the gun V-2. Likewise if E--2 is large compared to E---l, the grids of the devices V- l and V--5 are made more negative with respect to their cathodes, thus limiting the flow of their currents to a smaller part of the cycle, increasing the impedance of the transformer T--2 and decreasing the current of the gun V2.

Since the circuit of the devices V-' i and V--5 is arranged. to change from a firing angle of zero to 180 degrees when the voltage lit-3 varies over a few volts, the current of the gun V2 is stabilized at such a value that EI and E?. are approximately equal. The magnitude of the gun current required to fulfill this condition may be varied by adjustment of the resistor Err-2. As

the voltage E-3 is the resultant difference of two relatively large voltages E-I and E-2, a small change in gun current produces a relatively large change in the voltage E-3 so that the gun current is substantially independent of line voltage (and condition of cathode), the reference voltage E-l being maintained at a constant value by the voltage regulator V-l The present invention is thus characterized by the provision of means whereby a potential proportional to the output current of an electron discharge device is compared with a constant potential to derive a resultant potential by which the cathode heating current of such device is regulated to maintain its output current at a constant value determined by the adjustment of the regulating device.

We claim as our invention:

1. In a device for regulating the output current of an electron discharge device having a cathode coupled to be heated to a source of hea ing current, the combination of means for producing opposed unidirectional potentials one of which has a constant value and the other of which has a value proportional to said output current, a

riable impedance connected between said cathode and said source of heating current, means to control the value of said variable impedance, and means to continuously impress the resultant of said opposed potentials upon said control means to vary the value of said variable impedance and the heating current supplied to said cathode in accordance with fluctuations in said resultant potentials.

2. In a device for regulating the output current of an electron discharge device having a cathode coupled to be heated to a source of heating current, the combination of means for producing opposed unidirectional potentials one of which has a constant value and the other of which has a value proportional to said output current, means for smoothing out rapid fluctuations in the resultant of said opposed potentials, a variable impedance connected between said cathode and said source of heating current, means to control the value of said variable impedance, and means to continuously impress said smoothed out resultant potential upon said control means to vary the value of said variable impedance and the heating current supplied to said cathode in accordance with fluctuations in said resultant potential.

3. In a device for regulating the output current of an electron discharge device having a cathode coupled to be heated to a source of heating current, the combination of means for producing opposed unidirectional potentials one of which has a constant value and the other of which has a value proportional to said output current, means for smoothing out rapid fluctuations from the resultant of said potentials, a discharge device upon which said resultant potential is im-'- pressed for providing a shunt path under abnormal operating conditions of said device, a variable impedance connected between said. cathode and said source of heating current, means. to control the value of said variable impedance, and means to continuously impress said smoothed-out resultant potential upon said control means. to vary the value of said variable impedance and the heating current supplied to said cathode in accordance with fluctuations in said resultant potential.

4. In a device for regulating the output current or" an electron discharge device having a cathode coupled to be heated to a source'of heating: current, the combination of means for producing opposed potentials one of which has a constant value and the other of which has a value proportional to said output current, a transformer having a primary winding connected between said cathode of said discharge device and said course of heating current and a secondary winding, a pair of gaseous conduction electron discharge tubes, each having a grid, cathode and anode electrodes, said gaseous discharge tubes being push-pull connected to said secondary winding, and means for applying between the cathodes and control grids of said gaseous conduction tubes a potential which is the resultant of said opposed potentials to vary the current drawn by said gaseous conduction tubes proportionally to said resultant potential to vary the impedance of said transformer primary to cause heating current variations in opposition to variations in said output current.

5. In a device for regulating the output current of an electron discharge device having a cathode coupled to be heated to a source of heating current, the combination of means for producing 0pposed potentials one of which has a constant value and. the other of which has a value proportional to said output current, a pair of gaseous conduction electron discharge tubes each having a cathode, an anode, and a control gnid, a transformer having a primary winding connected between said source of heating current and said cathode of said discharge device and a secondary winding, said pair of gaseous conduction electron discharge tubes being push-pull connected to said secondary winding, means for applying between the cathodes and control grids of said gaseous conduction tubes a push-pull alternating current biasing potential, and means for applying between said gaseous conduction tubes, cathodes and control grids a potential which is the resultant of said opposed potentials to vary the current drawn by said gaseous conduction tubes proportionally to said resultant potential to vary the impedance of said transformer primary to cause heating current variations in opposition to variations in said output current.

SPURGEON H. BUDER.

WILLIAM H. EICHELBERGER.

REFERENCES CITED The following references are of record in the file of this patent:

, UNITED STATES PATENTS Olesen Sept. 24, 1946 

